CO-45 Denial Code: Charge Exceeds Contracted or Allowed Amount
Providers typically bill a standard charge that is higher than any single payer's allowed amount. When the payer applies its fee schedule, the gap between the charge and the allowed amount appears as CO-45. Because it is a contractual obligation, in-network patients cannot be billed for it.
The group code (CO, PR, OA, PI) tells you who is responsible. The CARC number tells you why.
CO-45 is not really a denial. It means your billed charge was higher than the payer's allowed amount under your contract or fee schedule, and the difference is a contractual write-off. Post it as an adjustment, and only dispute it if the allowed amount is lower than your contract says it should be.
Common causes of CO-45.
- Normal difference between your chargemaster rate and the contracted rate
- Payer applied an outdated or incorrect fee schedule
- Multiple procedure or other payment reductions applied
- Wrong provider or location loaded in the payer's system, triggering a different rate
How to work a CO-45 denial.
The order matters: confirm the facts before deciding between a corrected claim, a reconsideration, or an adjustment.
- 1Post the CO-45 amount as a contractual adjustment during payment posting.
- 2Compare the allowed amount to your contracted rate for that code and payer.
- 3If the payer allowed less than the contract, submit an underpayment dispute with the contract rate.
- 4Never transfer a CO-45 balance to patient responsibility on in-network claims.
How to keep CO-45 from coming back.
- Load contracted rates into your practice management system to flag underpayments automatically
- Review allowed amounts for top codes after every fee schedule update
Fixing this at the source usually sits with payment posting specialists →
Questions about CO-45.
Denials that often travel with this one.
CO-97: Service Bundled Into Another Service
CO-97 means the service was bundled into another procedure already paid. How to check NCCI edits and global periods, and when a modifier is appropriate.
Read about CO-97 →CO-96: Non-Covered Charge
CO-96 means the payer considers the service a non-covered charge. How to read the RARC, verify benefits, and decide whether to appeal or bill the patient.
Read about CO-96 →CO-204: Service Not Covered Under Current Benefit Plan
CO-204 (often PR-204) means the service is not covered under the patient's current benefit plan. How to verify benefits and handle patient responsibility.
Read about CO-204 →Add a Dedicated Denial Specialist
RCM Staff places trained denial management specialists inside your EHR and clearinghouse to work the queue, correct and appeal claims, and track root causes by payer.
Kevin Jamito has 18+ years of U.S. healthcare revenue cycle management experience across billing, coding, practice management, and offshore RCM operations. He founded RCM Staff to give U.S. healthcare teams dedicated Philippines-based specialists who work inside their existing systems.